Magneto



June 12, 1945.

H. G, cox ETAL MAGNETO 5 Sheets-Sheet l Filed June 25, 1942 Wggw June 12, 1945. H, G COX i-r AL 2,378,192

MAGNETO Filed June 25,` 1942 3 Sheets-Sheet 2 '7 INVENTORS ATTORNEY June 12, 1945.

H. G. cox E-rm. MAGNET Filed June 25, 1942 5 Sheets-Sheet 3 IN/ BY Q'M Lbbmw AT TORNEY y Patented June 12, 1945 UNITED STATES PATEIWV OFFICE MAGNETO Henry G. Cox, Hollywood-by-the-Sea, Fla., and Fred S. Slick, Rockford, Ill., asslgnors to J. I.

Case Company, Racine, Wis., a corporation Application June 25, 1942, serial No. 448,403

` 17 claims. (ci. 1v1-209) The present invention relates to magnetos and their component parts and an object thereof is to generally improve the construction and operation of devices of thisV class. A further and important object of the invention is to improve l the impulse coupling portion of a magneto.

More particularly an object is to provide for adjusting the point at which the impulse takes place and also to provide for positively maintaining such adjustment.

A further object is to provide a novel ange mounting for a magneto and for isolating the interior of the magneto from communication through the flange, withl the interior of the engine with which the magneto is used.

The manner in which this is accomplished is fully set forth in the following specification and accompanying drawings in which a satisfactory embodiment of the invention is shown. It is to be understood that the invention is not limited l to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention as herein expressed.

In the drawings,

Figure l is 'a vertical axial sectional view of a magneto embodying the invention.

Fig. 2 is an enlarged detail of' certain struc-- ture indicated in Fig. 1.

Fig. 3` is an elevation of an impulse coupling taken from the left in Fig. 1.

Fig. 4 is a front elevation of a portion of Fig.

I 1 with parts removed 'and others broken away.

Figs. 5 to 10 are sectional views taken on the line 5--5 of Fig. 1, showing the parts in various progressive positions constituting a cycle of opferation.

Fig. 11 is a sectional view on the line I I-II of Fig. l.

Eig. 12 is a similar view of a modified construction.

As seenl in Fig. 1, the magneto illustrative of the invention comprises a body portion I Il'including a ange II adapted for connection to a complementary flange I2 comprising a part o f an engine which drives the magneto and for which the magneto supplies the ignitionspark.

A coupling portion I3 within liange portion I2 is instance being the magnetized element ofthe.

magnetol and said shaft' is mounted in anti-friction or other suitable bearings generally des- Y. means 25 and 26. l

prevent the entrance of dirt, water, or other" ignated as I8 and I9 which support the shaft for rotation.

Bearings I8 and I9 are preferably of the sealed, permanently lubricated type of which numerous examples are well-known. An illustrative or preferred embodiment of bearings I8 and I9 may be constructed as shown in Fig. 2. In this construction each bearing has an outer race 2U, a series of balls 2I and an inner race `22. Outer race 20 in the present illustrative bearing is grooved and receives annular shielding plates 23 and 24 substantially closing the space between the races and enclosing balls 2I. Shields 22 and 24 are preferably tight in outer race 20 but do not contact inner race 22, the slight space between the two being closed by sealing members 25 and 26 of suitable resilient or elastic material. vThe space about balls 2I is charged with Va quantity of lubricant and which is prevented from escape by shields 23 and 24 and sealing The latter also eiectively deleterious material into the bearings.

Bearings such as this will run for very long periods without attention. y Shaft I6 carries a breaker cam 21 for actuating the breaker points, not shown, a gear 28 meshing with a gear29 for driving the distributor disk 30 all in well-known manner.

Magnet I1 rotates between pole pieces, one of which is indicated at 3I and which cooperate with a core portion v32 within a coil 33 for developing the necessary high voltage in well-known manner.

Shaft I6 is driven through an impulse coupling generally designated as 34 in the present instance within ange II.

The space to the right of flange I 2 is commonly open to the crank case of the engine although it is contemplated that it may be sealed therefrom by a partition 35, an oil' retainer 36 of any suitable type closing the space about a drive shaft 31. Shaft 31 drives coupling 34 which'in turn drives shaft I5. Shaft I 5 must therefore pass within housing I0 which makes possible the in- -advertent transmission of vapors, gases, etc.,

prevalent in the crank case into housing I0. In the present construction, this is prevented as follows.

As abovedescribed, bearing I9 is sealed against the exit of lubricant or entrance of foreign material. Housing II) and ange II are constructed with an opening 38 in the present instance downwardly open to the external atmosphere and extending upwardly to surround shaft I6. Spaced from bearing I3 an oil seal of suitable or wellknown type 33 engages shaft I6 toclose opening 38 from the interior of ange II. Thus any vapors, oil, or the like, 'within anges I I and I2 are prevented from escaping into opening 3B.

Seals such as 33 are very effective but are subject to wear under certain conditions. In case any oil or other material escapes past seal 39, in any manner, it is promptly thrown off by a fiinger surrounding shaft I6 and drained out through opening 38. In this Way any crank case oil. is kept away from bearing I9. Thus although bearing I9 is sealed and ordinarily would prevent the entrance of such crank case oil, the possibility of failure of the seal because of the impurities in the crank case oil is effectively avoided.

Magnetos of this general type are subjected to extreme fluctuation in temperature and at the same time it, is undesirable to provide any ventilation of the interior thereof for known reasons. Such temperature changes may possibly result in such changes of pressure of the air within housing l@ as to force air through the seal about bearing i5. Thus, if air is forced out when the magneto is hot, it follows that air may possibly be drawn in when the magneto cools. If this does occur, the air which finds its way into housing ID will be clean outside air drawn in through opening 38. In the past, in known constructions, crank case vapor containing acid and other damaging substances, has been drawn from the crank caseinto the magneto housing by an analogous action. This action is effectively prevented by the construction described including opening 38.

Magnetos in general depend upon a certain velocity of rotation in order to generate a suit able voltage for furnishing an ignition spark, and it is ordinarily inconvenient to produce such velocity under cranking conditions. Accordingly it is common to accelerate momentarily the rotation of the magneto parts at the instant the spark is needed by means of an impulse coupling.

Impulse couplings of known type have been subject to failure for several reasons and also have been difficult to adjust in order to obtain the impulse spark at the required retarded point in the engine cycle for most favorable starting conditions. Furthermore, they have been expensive to construct. In the present instance, an impulse coupling has been devised which overcomes these difficulties. Impulse coupling 34 is built largely on a hub portion 4l, which is a part readily made in quantity on automatic machinery. The remaining parts of the coupling are so devised that they can be readily made by inexpensive stamping operations. In this way, a coupling is provided which is substantially less expensive than heretofore known constructions. The coupling also has certain advantages in operation and in durability over heretofore known devices, the features responsible for these advantages being as follows:

The coupling comprises a driving element generally designated as 42 rotatably mounted on hub 4i and which drives, through a spring 43 a driven element generally designated as 44 xed on hub 4l. Spring 43 tends to rotate driven element 44 in a forward direction, maintaining it against stop portions and 46 carried by member 42. The driving and driven elements therefore rotate in unison in fixed relation to each other under normal running conditions. When the engine is being cranked and therefore turning substantially slower than its normal speed, driven element 44 is momentarily retarded, as will appear, so as to lag behind stop members 45 and 46. At the time the spark is required, member 44 is released whereupon spring 43 causes an extremely rapid partial rotation of member 44 until it again enlll gages stops 45 and 4B. During this rapid partial rotation the other magneto parts operate in wellknown manner to produce the spark. This spark normally starts the engine after which member 44 is steadily rotated in contact with stops 45 and 46. The speed of rotation is then high enough to generate the spark so that it is unnecessary to accelerate member 44 by means of spring 43.

Member 44, as best seen in Fig. 3, comprises a disk like element providing slots 41 and 48 extending circumferentially and spaced inwardly from the periphery of the disk. In the present instance, the slots open into outwardly directed notches or recesses 49 and50. Disk or driven member 44 forms a rear wall against which is disposed above mentioned driving member 42. The latter comprises a cup like element 5 l, Fig. l, journaled on a forward portion of hub 4I and rotatably engaged about the periphery of a disk 52. Thus driving member 5l is free to rotate relatively to hub 4| and driven member or disk 44. Stops 45 and 46 in the present instance are in the form of tongues extending rearwardly from the rim of cup like member 5I through slots 48 and 41 respectively.

For interrupting the rotation of driven mem ber 44, in the present instance, pawls 53 and 54 are journaled on pins 55 and 56 and have counterweights 5T and 58 disposed peripherally on the opposite sides of pins 55 and 56 from pawls 53 and `54. The pawls are very freely journaled on pins 55 and 56 so as to be iniluenced by gravity and centrifugal force. Thus in the position shown in Figs. l, 3, 4 and 5, counterweight 5T has dropped by gravity and swung pawl 53 outwardly of the periphery of disk 44. As the engine is cranked and coupling 34 rotated, in the direction indicated, driving member 42 and driven member 44 will rotate together, being held so by spring 43, until pawl 53 encounters an abutment generally designated as 59. This stops the rotation of disk 44 through pin 55, whereupon tongues 45 and 4Evcontinue to rotate in slots 48 and 4T as more particularly seen in Fig. 6, thus further increasing the tension in spring 43. At a predetermined point, tongue 46 encounters pawl 53 which has been resting against abutment- 59 and presses pawl 53 inwardly out of engagement with abutment `59, as indicated in Fig. 7. Disk 44, urged by spring 43, immediately starts to overrun driving member 42 thus initiating the desirable momentary rapid rotation of driven member 44. In Fig. 8, disk 44 has acquired substantially its full velocity and has nearly regained its original relation with tongues 45 and 46. The relative velocities of the two parts, driving and driven are indicated roughly by the length of the arrows showing the direction of rotation. The velocity of member 44 is sufficient to generate a positive spark for starting the engine. In Fig. 9, disk 44 has completely caught up with tongues 45 and 46 and the impulse action is completed. The engine has started, however, and the velocity of tongues '45 and 46 has increased roughly to that indicated by the arrow in Fig. 9. Centrifugal ,force now holds counterweights 51 and 58 in their extreme outward position so that pawl 54 which is now approaching abutment 53 will be retracted and will not engage the abutment. This is clearly shown in Fig. 10 in which pawl 54 is shown clearing abutment 59 by a generous amount. Pawl 53 also clears the abutment under these conditions as will be apparent.

As will now be clear, pawl 54 would operate 1n aavaiez substantially the same manner if the engine were cranked from a position where pawl 54 instead of pawl 53 was approaching abutment 59.

Abutment 59 as above stated is normally stationary but 'it will be apparent that the point in the rotation at which the pawls engage the abutment will determine the point in the cycle of the engine at which the starting spark occurs. In the present instance the location of abutment 59 is adjustable as will appear for the purpose of obtaining the desired timing of the starting spark.

Returning to a more detailed description of the parts, driving member 42 comprises a cup like member, as above stated, and has openings 6U and 6| through which project dogs 62 and 63 for engagement with slots 64 and 65 in above mentioned coupling member I3. In the present instance, dogs 62 and 63 are'iormed from a pair of C-shaped elements 66 and 61 disposed Within cup like member Member 56 has tongues 68 and 69 projecting forwardly through openings 68 and El respectively while member 61 has tongues 10 and 1l projecting forwardly also through openings 60 and 6|, although it is contemplated that dogs 62 and 63 might be made in one piece in the form of return bends, instead of in the two parts 68-10 and 69-1|, respectively. Tongues 68 and 10 constitute dog 62 While tongues 69 and 1| constitute dog 63. Member 66 is held in place in cup like element 5| in the present instance by rivets asv 12 engaged in suitable holes as 13 in members 5| and 66. In like mannery rivets as 14 and holes as 15 secure member 61 within member 5l. Dogs 62 and 63, in this manner, may be fabricated vfrom hardened steel or other suitable material for proper durability and which may be quite different from the material of cup 5| which would require, for example, certain particular Working characteristics.

Cup like element 5I is prevented from moving axially on hub 4i by a washer or similar element 16 clamped against the end of hub 4l, for example, by a nut 11 threaded on a portion 18 of above mentioned shaft I6. The pressure of nut 11 also holds hub 4l in place ona tapered shank portion 19 of shaft I6. A key 80 seated in shank portion 19 and engaging a keyway 8| maintains hub 4l and shaft I6 in the required relation. v

Pins 55 and 56 in the present instance constitute the means for uniting the several parts of driven member 44 with hub 4I. Thus pin 55 has a reduced shank portion 82 passing through disk v 44, a spacer disk 83 and above mentioned disk 52. Hub 4| has a shoulder 84 against which the several disks 44, 83 and 52 are seated. A disk 851s seated on the opposite side of shoulder 84 and urged toward disk 52 by above mentioned shank portion 82 which in the present in-- stance is riveted or otherwise suitably fastened to disk85., An identicall construction is associ ated with above mentioned pin 56 and. which it is 'not considered necessary to describe in detail. In this manner, the several disks are solidly mounted on hub 4l. As seen in Fig. Zi,l hub 4| has attened portions 86 and 81 for positively preventing rotary shifting of the parts. relatively to the hub'v under the considerable shock loads developed by the action of the coupling. Other non-circular shapes are contemplated aswith` there will be no possibility of their failing to rock about these pins under the action of gravity and centrifugal force, and Washers 81a and 81h are preferably interposed between pawls 53 and 54, and disk 44 to prevent dragging of the pawls or counterweights on disk 44.

As a further precaution against dragging or sticking, counterweights 51 and 58, as seen in Fig. 3, are indented at 81e and 81d so as to provide raised points 81e and 81j, Fig. 1. These points normally clear disk 44, but in the event of contact, prevent any appreciable area of the weights coming against the disk so as to minimize any tendency toward sticking, particularly if the parts are coated with cold oil.

Spring 43 is anchored in a channel-like fitting 88, Fig. 4 in the present instance united with the exterior of cup like member 5l in any suitable manner as by welding, and in the present instance has a hook portion 89 engaged about a lip 90 turned back, from a portion ci channel 88. An ear 9| is bent about spring 43 and positively prevents disengagement of the spring from the channel member regardless of .speed of rotation or other influences. In a similar manner, the opposite end of spring 43 is engaged in a channel portion 92 on a portion of disk 44, a similar hook portion 93 engaging a tongue 94 to posi- Abutrnent 59 in the present instance is part circular inv shape and struck up from a plate 95 engagedv Within flange il as more particularly seenin Fig. 11.

The shape of abutment 59 is such that the plane tangent to the 'abutment and containing the point of contact between the pawls and the abutment, is substantially at right angles to the line of thrust from the pivots or pins and 56 to the point of contact. In this Way, any tendency toward slipping oi of the pawls is avoided. Furthermore, engagement of the pawls is not dependent on sharp corners, and what wear is induced by enormous numbers of operations-will not alter the surfaces suiliciently to change the above relations appreciably, or cause failure of the pawls to remain engaged until disengaged by the tongues.

Plate has'a plurality of teeth 96--96 extending from the periphery thereof and which are engageable with teeth 91-91 formed in the periphery of a recess 98 in the back wall 99 of ange Il. Thus an exceedingly strong connection is provided between plate 95 and lflange ll so that inadvertent shifting of abutment 59 is impossible. Bate 95 is held in recess 98 in any suitable manner, inthe present instance screws Hi8-HI8, engaged in wall 99, engaging the edges of plate 95 to prevent axial displacement thereof. Axial displacement,.therefore, being impossible,

.plate 95 cannotbe shiftedexcept deliberately by removing screws |08', lifting the plate out of recess 98 and reinstalling it in the desired position. With screws |86 replaced, plate 95 then cannot shift from its new position. The position of abutment 59 is thus readily adjustable, but it cannot shift accidentally once the adjustment is made.

In adapting a magneto to various types of enginas, plate 95 is readily adjusted to thel proper position to give the most desirable amount of lag or retard to the spark desirable for starting that particular type of engine. For this purpose, a. pointer iii! is provided on plate 95 which registers with one or another of notations ||I2 according to the position in which plate 95 is installed. In practice, therefore, the degree of lag of the impulse coupling can be determined in advance by properly seating plate 95 according to notations In the present instance, the teeth in recess 98 are spaced at increments of 5 which is close magneto in various positions other than vertical i and as will be apparent this will necessitate re locating of abutment 59, perhaps beyond the range of adjustment possible in the embodiment of Fig. 11. Thus in aircraft practice, magnetos are frequently located up-side-down as related to the showing in Fig. 1, or possibly 90 from such showing. The invention facilitates such use as shown in the modification of Fig. 12. In this arrangement, a recess |03 is provided with teeth lOl-l 04 corresponding '1n general to above mentioned teeth 91 but extending completely around the periphery of recess |03. Plate 95 may therei fore be located in recess |03 in any position what-- ever within the increments determined by teeth |04. In this embodiment it would be inconvenient to utilize screws as IUI and accordingly` a l snap ring |05 is located in a groove |06 within a modified flange |01 and maintains plate 95 in adjusted position.A Platev 95 may be located wherever necessary in view of the position of the magneto after which ring |05 is allowed to expand into groove |05 and will maintain .the adjustment. Compensation is made in the other parts of the magneto for the new relative location of the impulse or tripping point as is well understood.

In magnetos of high power, it is essential to separate parts carrying the high output voltage appreciable distances from the metal parts of the magneto and at times this is difiicult because of space limitations. Thus. if -the voltageis such that the spark will jump for example, 3A" all metal parts must be separated at least this distance from any high voltage 'conductor unless separated therefrom by rugged insulation. Since the magneto must be made so that it can be taken apart, it is difficult to obtain this spacing between allparts and the exposed conductor.v In the present instance an auxiliary insulating mem. ber |08 in the form of a sheetv of dielectric acetate is interposed about coil 33'and between it and pole pieces 3| and frame I0. This adds'greatly tothe elciency of the insulation associated with coil 33 and forms a barrier against stray .dis`

charges from coil 33 to the adjacent metal parts of the magneto. f

The above being a complete description of the construction and operation of an illustrative embodiment of the invention, what is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a magneto, a housing portion and a flange adapted for mounting on an engine and in supporting relation to said housing portion, said housing portion providing a downwardly directed. vent opening, a shaft extending from said magneto housing portion through said flange for driving said magneto, said opening being arranged so as to expose said shaft between the interior of said magneto housing and said engine, sealing means about said shaft at one side of said recess, a dinger on said shaft within said recess, and sealing means at the other side of said recess.

2. In combination with an engine having a crank case, a magneto including a housing, a shaft in the housing, a member on the shaft within the housing rotatable with the shaft, a, bearing within the housing supporting the shaft for rotation, sealing means on the shaft spaced from the bearing, a flange on the housing and adapted to be mounted on the engine to support said magneto in communication with said crank case, coupling means on the shaft beyond said sealing means asrelated to said bearing and through which said magneto is driven from mechanism within said crank case, and said housing being so shaped as to provide a draining recess extending from said shaft between said bearing and said sealing means to the outside of said housing- 3. In a magneto having a housing and a shaft in the housing, the combination of a rotor on the shaft, a bearing supporting the shaft for rotation in the housing, sealing means on the shaft spaced from the bearing, a flange on the housing spaced from the sealing means and adapted to be mounted on an engine, coupling means on the shaft beyond the sealing means, and said housing being so shaped as to provide a recess extending from said shaft between said bearing and said sealing means to the outside of said housing.

4. In a magneto including a housing portion and an impulse coupling associated with said housing portion and including a plate, an abutment on said plate positioned to engage parts of said coupling, means for tripping the latter to produce an 'accelerated movement in said maneto, interlocking teeth on said plate and said housing adapted to positively prevent rotation of said plate, said teeth being disengageable from each other by axial movement of said plate for rotation and installation in another position, a screw engaged in said housing and having a head overlapping said plate for preventing axial displacementof said plate for maintaining the adjustment thereof, and dial and pointer means on said plate and said housing for indicating the effect on the impulse timing of installation of said plate in various positions.

5. In -an impulse coupling including a housing portion and a rotative portion, an abutment carrying element, an abutment on said element positioned to engage parts of said rotative portion for preventing rotation thereof, means for tripping said parts to produce an accelerated movementin said magneto, disengageable means for holding saidv abutment carrying element in said housing portion, interlocking surfaces on said element and said housing portion positioned t0 positively prevent rotation of said element independently'of said holding means, said surfaces being disengageable from each other by axial 4in contact for driving said movement of said element for rotation and installation in. another position upon disengagement of said holding means.

6. In a magneto, including a housing portion and an impulse Icoupling associated with said housing portion, a plate, an abutment on said plate positioned to engage parts of said coupling,

means for tripping the latter to produce an accelerated movement in said magneto, interlocking teeth on said plate and housing portion, having surfaces extending substantially in the direction of the axis of said impulse coupling, and

adapted to positively prevent rotation of said plate, said teeth being disengageable from eachl other by axial movement of said plate for rotation and installation in another position, a screw engaged in said housing and having a head overlapping said plate for preventing axial displacement of said plate for maintaining the adjustment thereof, and 'dial and pointer means on said plate and said housing for indicating the eiect n' the impulse of installation of said plate Y in various positions.

7. In an impulse coupling, including a housing portion, a plate, an abutment on said plate positioned to engage partsof said coupling for preventing rotation thereof, means for tripping said parts to produce an accelerated movement in said magneto, interlocking surfaces on said plate and housing substantially parallel to the axis of said impulse coupling adapted to positively prevent rotation of said plate, said -surfaces being disengageable from each other by axial movement of said plate .forrotatign and installationin another position. andgmeans for preventing inadvertent axial displacement of said plate for maintaining the adjustment thereof.

8. In'an impulse coupling for a magneto for mounting on an engine, a. driving element comprising a cup like member and a C-shaped elemaintain said stop means in contact for driving said driven member from said driving member.

12. In an impulse coupling a driven member comprising a hub having a nange or shoulder intermediate the ends thereof, a driven disk on one side of said ilange, an anchoring disk on the other side of said flange, a plurality of pins carried by said disks, pawls journaled on said pins for actuating said impulse coupling, and said pins' being adapted to unite said disks and to clamp them into intimate contact with said flange.

13. In an impulse coupling, a driven member comprising a hub having a ilange or shoulder intermediate the ends thereof, a driven disk on one side of said ilange, an anchoring `disk on the other side of said ange, and tension means uniting said disks and clamping them into intimate contact with said flange.

14. In an impulse coupling, a driven member, including a hub, a disk on the hub, a second disk adjacent the ilrst disk and having an outer periphery adapted to constitute a bearing portion, a journal portion on said hub andl spaced from said disk, and a driving member comprising a cup-like element iournaled on said journal portion and on the second mentioned disk, a tongue on said cup-like element extending beyond the ilrst mentioned disk,a stop on said first mentioned disk; and spring. means connected for holding said tongue yieldingly in contact with said stop.

15. In an impulse coupling having a vdisk-like driven element, a pin on said disk-like element, a pawl pivoted on the pin, and a-counterweight element connected with the pawl and disposed on the opposite side of said pin from said pawl, and

ment within'the cup likemember and having outturned ends projecting through the wall oi.' 1 the' cup like member toward said engine and forming driving dogsto receive the drive from the engine with which the magneto is associated. 9. In. an impulse coupling for a magneto. a

Jecting through the wall of 'said cup like mem- 'driving element comprising a cup like member "and an element disposed within the vcupi like' 'memben and having an outturned portion prober to form a driving dog to receive the drive from an engineV with which said magneto is associated.

10.` In an impulse coupling opposed l'axially spaced driving and driven members,` said driven member being rotatable relatively to said driving member, stop means on said members adapted to maintain them in-ilxed rotative relation to each other. and spring means coiled about the outside of said members, having oppositeendsconnected respectively to opposite members and tensioned to yieldingly maintain said stop means driven member from said driving member.

11. In an impulse coupling, opposed axially spaced driving and. driven members. said driven member being rotatable relatively to said driving member, stop means on said members adapted `to maintain them in lfixed rotativerelation to eachl other, a 'channel on one of said members.

andasprlngengagedin-saidchannelandhava ing itsoppoeed ends connected respectively to opposite members and tending to yieldingly ciated with 'said channel and engaged with said hook portion for anchoring said spring wire in said channel, and said spring wire having its opposed ends'connected respectively to `opposite members and tending to yieldingly maintain said stop means ln contact for driving said driven member from. said driving member.

17. In 'an impulse coupling, opposed axially spaced driving and driven members, said driven member being rotatable relatively to said driving member, stop means on said members adapted to maintain them in xed rotative relation to each other, a. channel -on vone of said members, a

spring wire engaged in said channel and having its opposed ends connected respectively to opposite members. an ear on said'channel shaped to enclose a portion ot said spring wieto prevent -dislodgement of the wire from said channel, said wire having its opposedends connected respectively to opposite members and tending to" yield- '.ingly maintain saidstopmeans in for driving said driven' member from said driving mmRYaoox. ramasucx.

' member'. 

